• Journal of IKEEE
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• v.23 no.2
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• pp.628-635
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• 2019

This paper proposes sliding mode control (SMC) method for improvement of dynamic response for IPMSM based on DTC with constant switching frequency. DTC with constant switching frequency method consists of PI torque controller and triangular comparator for constant torque error status. It has the poor dynamic response compared to conventional DTC. This paper proposes improvement method of dynamic response of DTC with constant switching frequency by using SMC. Simulation results confirm the effectiveness of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.474-477
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• 1995

In this paper, the nonlinear model of axial electro-magnetic suspension(EMS) system is presented. The characteristic of attracyion force is analyzed by FEM. Some simulation is given to compare the sliding mode control based on the input-output linearization with the classical linear control using Taylor approximation. Real result of regulating control, transient response comparison, and robustness control with disturbance using the sliding mode method is presented.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1060-1061
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• 2015

This paper presents the control method of MPPT (Maximum Power Point Tracking) using back-to- back converter. The windturbine system use PMSG(ermanent Magnet Synchronous Generator) system considering low maintenance costs and driving performance at low wind. This paper use the adaptive sliding mode control to the torque control. Proposed method was analyzed mathematically.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.613-614
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• 2009

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.212.1-212.1
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• 2005

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.747-753
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• 2005

In this paper, as an anti-sway control strategy of container cranes, we investigate a variable structure control in which the moving load follows a given trajectory, whereas both the trolley and hoist controllers achieve their positioning problems. It is crucial, in an automated container terminal, that collisions should be avoided during the transference of containers from one place to another. It is also necessary, in the case of a quay crane, to select suitable loading and unloading trajectories of containers, so that possible collisions with surrounding obstacles are avoided. After a brief introduction of the mathematical model, a robust control scheme (i.e., a second-order sliding mode control that guarantees a fast and precise transference and a suppression of the resulted swing) is presented. Despite model uncertainties and unmodeled actuators dynamics, the swing suppression from the given trajectory is obtained by constraining the system motion on suitable sliding surfaces, which include both the desired path and the swing angle. The proposed controller has been tested with a laboratory-size pilot crane. Experimental results are provided.

• Journal of IKEEE
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• v.9 no.1 s.16
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• pp.47-56
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• 2005

A new improved robust variable structure tracking controller is presented to provide an accurately prescribed tracking performance for brushless direct drive(BLDD) servo motors(SM) under uncertainties and load variations. A special integral sliding surface suggested for removing the reaching phase problems can define its ideal sliding mode and virtual ideal sliding trajectory from an initial position of SM. The tracking error caused by the nonzero value of the sliding surface is derived. A corresponding continuous control input with the disturbance observer is suggested to track a predetermined virtual ideal sliding trajectory within a prescribed value under all the uncertainties and load variations. The usefulness of the proposed algorithm is demonstrated through the comparative simulations for a BLDD SM under load variations.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.127-134
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• 2015

In this note, a continuous sliding surface transformed variable structure systems by the saturation function is presented for MIMO uncertain linear plants. A discontinuous sliding surface transformed VSS is proposed theoretically. The closed loop exponential stability together with the MIMO existence condition of the sliding mode on the predetermined sliding surface is investigated. For practical applications, a continuous approximation of the discontinuous VSS is made by means of the saturation function. The discontinuity of the control input as the inherent property of the VSS is much improved in view of the practical aspects. Through a design example and simulation studies, the usefulness of the proposed continuous transformed VSS controller is verified.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.8
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• pp.1173-1182
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• 2001

Recent noticeable advances of CNC machine tools have considerably improved productivity and precision in manufacturing processes. However, in the respect of productivity some defects still remain because selection of machining conditions entirely depends on the experiences of programmers. Usually, machining conditions such as feed rate and spindle speed have been selected conservatively by considering the worst cases, and it has brought the loss of machining efficiency. Thus, the improvement of cutting force controller has been done to regulate cutting force constantly and to maximize feedrate simultaneously in case that machining conditions change variously. In this study, sliding mode control with boundary layer is applied to milling process for cutting force regulation and in a commercial CNC machining center data transfer between PC and PMC (programmable machine controller) of CNC machine is done using a standard interface method. And in the cutting force measurement, an indirect cutting force measuring system using current signal of AC servo is adopted in order not to use high-priced equipment like tool dynamometer. The purpose of this study is to maximize the productivity in milling process, thus its results can be applied to cases such as rough cutting process.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.38-44
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• 2002

A walking training robot is proposed to provide stable and comfortable walking supports by reducing body weight load partially and a force control of an arm of walking training robot using sliding mode controller is also proposed. The current gait training apparatus in hospital are ineffective for the difficulty in keeping constant unloading level and for the constraint of patients' free walking. The proposed walking training robot effectively unloads body weight during walking. The walking training robot consists of an unloading manipulator and a mobile platform. The manipulator driven by an electro-mechanical linear mechanism unloads body weight in various levels. The mobile platform is wheel type, which allows patients to walt freely. The developed unloading system has advantages such as low noise level, lightweight, low manufacturing cost and low power consumption. A system model fur the manipulator is established using Lagrange's equation. To unload the weight of the patients, sliding mode control with p-control is adopted. Both control responses with a weight and human walking control responses are analyzed through experimental implementation to demonstrate performance characteristics of the proposed force controller.